Internal combustion engine



May 19, 1931. J. H. PIERCE INTERNAL COMBUSTION ENGINE Filed Nov. 5, 1.928 3 Sheets-Sheet 1 .54 6!. a J :TT TORNE Y y 1931- J. H. PIERCE 1,805,843

INTERNAL COMBUSTION ENGINE Filed Nov. 5. 192B 3 Sheets-Sheet 2 75' I0 13- m =7 7 2 2 2 v/mxxx Y Y x x w g/Q m VENTOR JAMES H PIE/2c:

A TTORNE V May 19, 1931.

J. H. PIERCE INTERNAL CGMBUSTION ENG INB Filed Nov. 5, 1928 3 Sheets-Sheet 3 T as! I 59 s7 '38} 4 I v "'.L 39 l Him a7 7 I z L 4/ I I 1 III 5 3/! 2 as as as a! 30 26 90* I 89 r 94 V 93] 99 97 f 98 92 26 I 89 I 97 :E.L 9-13 [fl WWW Patented May 19, 1931 JAMES H. PIERCE, 01? BAY CITY, MICHIGAN INTERNAL COMBUSTION ENGINE Application filed November 5, 1928. Serial No. 317,212.

This invention relates to internal combustion engines and particularly to engines of the two-cycle type wherein a gas is drawn into the crank case and compressed, and thereafter delivered to the cylinder for combustion; the principal object being the provision of a new and novel means for controlling the passage of the gas into the crank case.

Another object is to provide an internal combustion engine of the type described adapted to be positioned with the axis of the crank shaft in a generally vertical position,

and provided with a valve member located within the crank case and co-operable with a port in the upper wall of the crank case to control the flow of gas into the crank case.

Another object is to provide an engine of the typeydescribed having a crank case wall disposed perpendicularly with respect to the axis of the crank shaft, and havin a port therein, a member being carried by the crank shaft for equal rotation therewith and formed to limit the flow of gas into the crank case through the port to certain rotational positions of the crank shaft, resilient means being provided for maintaining the member in contact with the wall.

Another object is to provide a novel supercharger for internal combustion engines.

Another object is to provide a combined valve and supercharger device for internal combustion engines.

A further object is to rovide a new and novel means for controlling the flow of gas intothe crank case of an internal combustion engine of the two cycle type.

The above being among the objects of the present invention, the same consists in certain features of construction and combinations of parts to be hereinafter described, with reference to the accompanying drawings, and then claimed, having the above and other objects in view.

In the accompanying drawings which illustrate a suitable embodiment of the pres ent invention, and in which like numerals refer to like parts throughout the several different views;

Fig. 1 is a vertical sectional view taken through the axis of a two cylinder opposed internal'combustion engine of the two-cycle Fig. 2 is a fragmentary sectional view taken on the line 2-2 of Fig. 1 and showmg the ports in one of the cylinders and pistons thereof.

Fig. 3 is an enlarged view of the upper wall of the crank case of the engine shown in Fig. 1, taken looking at the under face thereof.

Fig. 4 is a sectional view taken on the line 44 of Fig. 3.

Fig. 5 is an enlarged fragmentary partially broken view of the crank and cooperating valve member shown in Fig. 1.

Fig. 6 is a view taken on the line 6-6 of Fig. 5, the valve disc being shown in section, and the crank arm being partially b'oken away to show certain features there Fig. 7 is a plan view taken on the line 7-7 of Fig. 5 and showing the upper crank case arm in plan view.

Fig. 8 is a sectional view taken on the line 88 of Fig. 5 and showing the valve disc in plan view.

Fig. 9 is a plan view of a modified form of valve disc.

Fig. 10 is a fragmentary developed sectlonasl view taken as on the line 1010 of Fig. 11 is an enlarged fragmentary sectional view similar to Fig. 5, and showing another modified construction.

Fig. 12 is an enlarged fragmentary sectional view taken through the axis of the crank shaft of an internal combustion engine, having a modified form of disc valve.

Fig. 13 is a fragmentary view showing a modified means of resilient support for the crank shaft in the construction shown in Fig. 12.

The present invention deals with a valve construction of the general type disclosed in my application for Letters Patent of the United States for improvements in marine propulsion device filed July 5th, 1928 and serially numbered 290,563, and relates particular'ly to an improved construction for the same.

In the above identified patent application, an internal combustion engine of the two cycle type is disclosed which is rovided with an a rtured disc in the cran case thereof whic cooperates with a port in the bottom wall of the crank case to control the flow of combustible mixture into the crank case. I have found that it is desirable for various reasons to bring the gas through the upper wall of the crank case instead of the lower wall thereof, and the present invention relates to means for accomplishin this result.

Referring to the accompanying drawing and particularly to Figs. 1 and 2, I show an internal combustion engine designed particularly for use in connection with outboard motors, but which is obviously adaptable to other purposes, provided with a base or crank case 25, and having a lower wall 26 and an upper wall 27 formed to be removable therefrom and secured in place by screws such as 28 and 29 res ectively. The lower wall 26 is )rov ded wit 1 an extension 30 in which the aring 31 of the vertically disposed crank shaft is suitably journaled, and which may be surrounded by a suitable sleeve (not shown) when the engine is employed in connection with an outboard motor, so that the motor may he turned to effect the steering of the boat. The upper wall 27 is likewise provided with an extension 32 in which the upper bearing 33 of the crank shaft is suitably journaled. Secured to two diametrically op site sides of the crank case 25 are a pair 0 cylinders 34, each of which is pro- "ided with a piston 35. The pistons 35 are connected through the pins 86 and connecting rods 37 to the crank pins 38 disposed on diametrically opposite sides of the axis of the crank shaft and connected to the bearing portions 31 and 33 through the throws 39, 40 and 41. The throws 39, 40 and 41 shown in 'the drawin are of disc like formation, although it wi 1 be apparent that they may be formed in' the more conventional manner if desired, and in the latter case the openin provided in the disc 40 for the passage 0 gas, as hereinafter described in connection with a separate valve disc, will of course be automatically eliminated.

In the construction shown in Fig. 1 the crank shaft is supported against axial movement in the cran ease by a thrust washer 42 interposed between the lower crank case wall 26 and the adj acent crank arm 42.

As in the conventional type of two-cycle engines, combustible mixture is drawn into the crank case while the istons 35 are travelling away from each 0 er, in this case in a manner which will be presently described and such combustible mixture is compressed du the return movement of the pistons tow each other, the pistons being provided with ports such as 44 cooperating with passa es such as 45 in the cylinders as illus- Irate in Fig. 2, to permit the compressed gas to escape into the cylinder when the pistons approach and have reached the lower limit of their stroke. The cylinders are of course also provided with exhaust ports such as 46, permitting the escape of burned gases from the cylinder.

In accordance with the present invention, the flow of combustible mixture into the crank case is controlled in a novel manner. The upper wall 27 is provided with a wort o ning 47 therethrou h as illustrate in Figs. 3 and 4, and on the upper side of the wall 27 a duct- 48 is formed which communicates with the port opening 47, and which terminates in a flange end 49 adapted to be connected to a carburetor. Surrounding the bea ring portion 33 of the crank shaft within the crank case between the up r throw. 40 and the upper wall 27, and axially slidable relative to the bearing 33, is a disc 50 which is shown as being of substantially the same diameter as the throw 40. The disc 50 is provided with an eccentric opening 51 therein disposed axially of'the crank shaft, and the throw 40 is provided with an axially extending pin 52 fixed therein, and which is slidably received in the opening 51 so as to drive. the disc 50 at the same rotational speed as the crank shaft, without restricting t 1e axial movement of the disc 50. As indicated in Fig. 6, the disc 50 is provided with one or more blind openings 53 opening downwardly therein and the upper throw 40 of the crank shaft is rovided with a like number of blind openings 54 opening upwardly therein and positioned in alignment with the openings 53, and within each pair of aligned openings 53 and M a coil spring 55 is received and maintained under comression between the blind end thereof.

1e springs 53 are of suilicicnt strength to overcome the weight of the disc 50, and constantly urge the same a ainst the lower surface of the upper wall 2 although it is referable that they should merely cause the disc 50 to bear against the wall 27 and not exert an apprecia le amount of pressure against it, as will be explained later.

Referring to Figs. 7 and 8, the disc 50 is provided with a circularly extendi slot or port 58 therein, the outer and inner imits of the port 58 radially of the disc being commensurate with the outer and inner limits of the rt 47 in the wall 27 with respect to the axis of the crank shaft, and the upper throw 40 of the crank shaft is provided with an aligned port or o ning 59 of like dimensions. The circum ercntial length of the ports 58 and 59 and the rotational position ofthesamewithrespecttothecrankshaft is preferably such that when the pistons 35 begin their travel outwardly in the cylinders ill) 34 the leading edge of the port 58 begins to uncover the port 47, and the port 47 remains uncovered until the pistons reach the outer end of their stroke at which time the trailing edge of the port 58 completely passes over the port 0 ening 47, and thereafter the solid portion 0 the disc 58 closes the port 47 to the flow of gas until the pistons 35 again reach the inner limits of their travel. This arrangement of ports is shown in the drawings when the valve and crank are rotating in the direction of the arrows shown in Figs. 7 to 9 inclusive. It will thus be seen that the port 47 is substantially fully open to the flow of combustible mixture into the crank case during the entire time that the pistons are moving away from each other, and is closed during the entire time that the pistons are approaching each other in order that the gases that have been brought into the crank case during the outward movement of the pistons may be compressed and be put in condition to be forced through the ports 44 and 45 to the cylinders when the pistons approach the inner limit of their travel.

Due to the fact that the port 47 is uncovered by a disc 50 during outward movement of the pistons when a suction is created within the crank case, during which time it is immaterial whether or not the disc 50 lies in contacting relationship with the lower surface of the wall 27, and further due to the fact that when the disc 50 has closed the port 47 the pistons are approaching each other and putting the gas in the crank case under compression pressure, which pressure acting against the disc 50 acts to force it into more intimate contact with the end wall 27, it will be apparent that the springs 55 need only to be of suflicient strength to cariy the weight of the discs 50 at a height su cient to cause the disc 50 to substantially contact with the wall 27 without exertin a material pressure a ainst such wall. T is insures complete sea ing of the port 47 during the compression stroke without subjecting the rubbing surfaces to excessive pressures.

Inasmuch as engines of this type enerally mix the lubricating oil with the uel before it is delivered to the carburetor, it will readily be apparent that the oil in the fuel, in coming in contact with the disc 50 during its'passage through the port 47, will provide ample lubrication for the wearing surfaces between the disc 50 and the wall 27.

This form of valve arrangement readily lends itself to a simple and efficient manner of supercharging the engine at a ver slight additional cost. The manner in which this may be done is shown in Figs. 9 and 10. In this Case a disc 62 is provided in place of the disc 50. The disc 62 is shown as being of the same diameter as the disc 50 and trailing edge 76 provided with openings 52 and 54 for reoeption of the. driving pin 52 and springs 55 respectively as in the previous case. The disc 62 is provided with an o ening 63 identical with the opening 58 1n all respects, except that in t e particular embodiment shown in Figs. 9 and 10 the trailing edge 64 thereof is extended circumferentiall around the disc to a greater extent than t e opening 58, so that the port 47 will not be closed untilafter the pistons have started on their return stroke. The corresponding opening in the upper crank case disc in this case will of course have to be extended to correspond with the opening 63. Within the opening 63 is positioned a plurality of blades 65 to 72 inc usive which may extend radially of the disc as shown. The blades 65 are ositioned angularly so as to serve as fan I) ades so that in rotating past the port 47 during running of the engine, they will serve to accelerate the flow of ases through the port 47. The leading and trailing edges of the openings 33 are preferably beveled oil as at 75 and 76 respectively so as to blend in with the general arrangement of the various blades. The gases enterin the crank case through the port 47 are 0% course induced to flow by the suction created by the pistons in their separatin movements, and it is therefore necessary t at the angle of the blades 65 to 72 inclusive be such as to produce a material suction of the gases in the passage 48 in addition to the normal suction created by the piston movement at a maximum engine speed.

It will further be apparent that the suction caused by the piston movement will vary from minimum at the inner and outer ends of the stroke to a maximum at a point approaching midway the inner and outer limits of the piston travel, at which time the pistons are separating from each other at maximum speed. For this reason the blade 65 which first passes over the port 47 and the blade 72 which last passes over the port during the suction stroke of the engine are positioned at a more acute angle with respect to the face of the disc than the blade 68 which will be positioned approximately at the center of the ort 47 when the pistons are travellin at tli eir greatest s ed, and the various bliides between the bladifs 65 and 68, and 72 and 68, will vary in their angularity with res ct to the surface of the disc in a correspon 'ng manner. It is also referable, as shown, that the angularity o the fan blade, be reater than the angularity of the blade 65, For the reason that the moment the ort 47 begins to be opened by the disc 62 t e gases in the passage 48 are approximately at rest, while the gases in this passage at the time the disc 62 closes the port 47 may still be in the state of movement, so that which in itself serves as a the trailing edge 76 will thus be formed to act on gases alread having a flow, and accelerate such flow. iurthermore, all of these blades increase in angularity from the outer ends to their inner ends to compensate for the difference in linear speed at these points during rotation.

As previously mentioned the trailing edge 64 of the o ning 63 in the disc 62 is extended circum erentially of the disc to a greater extent than the trailing edge of the opening 58 in the disc 50, for the reason that at high engine speeds it usuallg occurs that when the pistons have reache the outer limits of their travel there still remains a partial suction within the crank case, andshould the ort leading into the crank case be left open or a short period, even after the pistons have started to move on their return stroke, a greater volume of as might enter the crank case before the pistons bggan to act to compress the gases in the era case. For this reason the opening in the disc controlling the opening of the port 47, even when the blades 65 to 72 are not employed, may be extended as indicated in Fig. 9 so that the port 47 will remain uncovered until after the pistons have begun to move toward each other. The use of the blades 65 to 72 in such cases are extremely beneficial inasmuch as they may be employed to raise the pressure of the gas in t e crank case to a point materially above atmospheric ressure by the time the port 47 is closed to a low the gas to be compressed.

The blades 65 to 72 inclusive as shown in Figs. 9 and 10 may be either cast, welded, or otherwise suitably secured in place within the o ning 63. simplified manner of provi ing these blades is indicated in Fig. 11. As indicated in this Fig. a sheet metal or other sleeve liner 77 is formed to slidably fit the openings 58 and 59 in the disc 50 and throw 40 respectively and is preferably provided with a tlange such as 78 which may overlie a surface of the throw 40 as shown, or the disc 50 if desired and may be removably secured thereto by screws such as 79 or other suitable means. The liner 77 is preferabl of a depth substantially equal to the com ined thicknem of the disc 50 and the throw 40. Within the liner 77 may be secured a plurality of fan blades 80, similar to those shown in Figs. 9 and 10, secured in place by any suitab e means. In this construction the hner 77 and blades 80 may be formed separately from the disc 50 and throw'40 and thereafter be secured in lace. This construction readily lends to the provision of various removable liners 77 havinglrlades 80 therein of various pitcbmso t 1: they maybe substituted for each er to obtain optimum results.

Although I have shown and described the above mechanism in connection with an engine of the two cycle type, it is readily apparent that in some cases it may be desirable to employ a like structure for effecting a superchar 'ng of engines of the four cycle type, and therefore do not limit this feature of my present invention to two cycle en 'nes.

It wil be apparent, of course, that where the throw 40 is in the form of a disc, the disc 50 may be eliminated, and by suitably sup orting the crank shaft the throw 40 be utihzed to control the flow of gas through the port 47 without employing the disc 50. Such a construction is illustrated in Fig. 12. In this case the upper surface of the throw 40 contacts against the lower surface of the end wall 27 and the opening 59 in the throw 40 cooperates directly with the port 47 to control the flow of gas into the crank case in exactly the same manner as that previousl described in connection with the disc 50. n such a case it is referable, if not necessary, to provide resilient means for maintaining the throw 40 in contact with the wall 27. This is accomplished in the following manner in Fig. 12:

The lower wall 26 of the crank case is provided with an axially eiitending upwardl openin recess 85 therein concentric with t e lower caring 31 of the crank shaft. Seated in the bottom of the recess 85 is a ball thrust bearing 86 and surrounding the bearing 31 of the crank shaft immediately below the throw 41 is another ball thrust bearing 87. 'A coil spring 88 surrounding the bearing 31 is maintained under compression between the ball thrust bearings 86 and 87 and therefore constantly urges the crank shaft upwardly. The spring 88 must, of course, be of suflicient strength to carry the weight of the crank shaft and any parts that may be fixed thereto, such as the fly wheel (not shown), magneto (not shown), and any other parts.

In order to eliminate the weight of the drive shaft 89 from the weight the spring 88 must support, the drive shaft 89 is provided with suitable s lines 90 which are slidably but non-rotatab Iyereceived within the hollow interior of the aring portion 31, and the drive shaft 89 may be supported independentl' of the crank shaft in the same manner as t shown in my previous patent application above referred to, or by other suitable means.

As in the case where the disc 50 is emplo the spring means, which in this case is t e sprin 88, which holds the disc 40 in contact wit the wall 27, is preferably of only suflicient strength to maintain such contact without causing an appreciablepressure to be exerted between the contacting faces of the throw 40 and the wall 27.

It will be apparent that with the construction shown in Fig. 12 unless some means were provided to overcome the shocks transmitted to the engine in a direction parallel to the axis of the crank shaft, such shocks might cause axial displacement of the crank shaft sufiiciently to interfere with the proper functioning of the disc 40 and opening 47 and mightsubject the parts to undesirable hammering. With the construction as shown in Fig. 12 the upper thrust bearing 87 looselyengagcs the walls of the recess 85, and in operation oil that is separated out from the combustible mixture collects in the bottom of the crank case and fills the recess 85. \Vhen this happens, if a shock is transmitted to the engine in the direction of the axis of the crank shaft so as to tend to move the throw 40 away from the wall 27, the thrust washer 87 will act like a piston and the recess 85 as a cylinder, and the oil which is trapped in the recess 85 below the washer 87 will dampen any tendency of the crank shaft toward axial movement relative to the crank case. This cooperation between the washer 87 and the recess 85 aifords an effective damping means for axial movements of the crank shaft.

Where it is desired to modify the pressure of the spring 88 on the crank shaft, shims such as 91 may be inserted or removed from between the thrust bearing 86 and the cooperating end wall of the recess 85, as will readily be apparent.

In the construction shown in Fig. 12, the employment of the washers 86 and 87 and spring 88 act to increase the distance between the bearing points for the lower crank shaft bearing 31 and upper crank shaft bearing 33, and in some cases this may be obectionable as tending to increasethe bendmg stresses to which the crank shaft may be subjected. In such a case the construction illustrated in Fig. 13 may be resorted to. In that figure the lower wall 26 is formed to provide a journal for the bearing 31 imme iately ad acent the lower throw 41 and below the portion 31 of the crank shaft is reduced in diameter as at 92 .to form a shoulder 93 against which a thrust bearing 94 is adapted to seat.

The lower end of the extension 30 of the wall 27 is enlarged and is interiorly recessed as at 95 and connected by screws such as 96 to a housing member 97 which extends downwardly therefrom. A second thrust washer 98 is seated against the upper end of the housing portion 97 and a coil spring 99 held under compression between the washers 94 and 98 is provided for maintaining the crank shaft in proper axial position. In both constructions shown in Figs. 12 and 13 the lower housing portions 97 are provided with radial flanges 100 which serve to carr the weight of the motor on a sleeve (not s own) which is adapted to rotatably encase the portions 97.

Formal changes may be made in the specific embodiment of the invention described without departing from the spirit or substance of the broad invention, the scope of which is commensurate with the appended claims.

\Vhat I claim is:

1. In an internal combustion engine, in combination, a crank case provided with an intake port in a wall thereof, a crank rotatable in said crank case, a member rotatable with said crank and co-operating with said port to control the flow of gas into said crank case, said member having an opening re istering with said port during predetermined rotational positions of said crank to permit the flow of gas through said port, and fan blades arranged in said opening to accelerate the flow of gas through said port into said crank case.

2. In an internal combustion engine, in combination, a crank case, a crank rotatable therein, said crank case being provided with a wall perpendicular to the axis of said crank and having an intake port therein, means rotatable with said crank in sweeping cooperation with said port to close it to the passage of gas during certain rotational positions of said crank, and means rotatable with said crank co-operating with said port to accelerate the flow of gas therethrough into said crankcase during other rotational positions of said crank.

3. In an internal combustion engine, in combination, a crank case, a crank rotatable therein, said crank case being provided with a wall perpendicular to the axis of said crank and having an intake port therein, means in said crank case rotatable with said crank co-operating with said port to control the passage of gas therethrough, said means having anopening therein co-operatingwith said port during predetermined r1 tiltlOl'ml positions of said crank to permit ;he flow of gas through said port, and fan Hades of the axial flow type arranged in sad opening and rotatable with said means for accelerating the flow of gas through s: 1d port.

4. In an internal combustion en gine, in combination, a crank case, a crank lotatable therein, said crank case being provided with a. wall perpendicular to the axis of said crank and having an intake ort therein, means in said crank case rotata le with said crank co-operating with said port to control the passage of gas therethrough, said means having'an opening therein co-operating with said port during predetermined rotational the flow 0 gas through said port, and fan blades arranged in said opening and rotatable with said means for accelerating the flow of gas through said port, the pitch of said fan blades varying circumferentially of said crank.

ositions of said crank to permit 5. In an internal combustion engine, in combination, a, crank case, a crank rotatable therein, said crank case being provided with a wall per endicular to the axis of said crank and aving a ort therein, means in said crank case rotata le with said crank cooperating with said port to control the passage of gas therethrough, said means having an opening therein co-operating with said port during predetermined rotational positions of said crank to permit the flow of gas through said port, and fan blades ar ranged in said opening and rotatable with said means for accelerating the flow of (gas through said port, said blades being of ifferent pitches and arranged with the blades of greatest pitch adjacent the radial centerline of said opening.

6. In an internal combustion engine, in combination, a crank case, a crank rotatable therein, a cylinder secured to said crank case, a piston in said cylinder operatively connected to said crank, said crank case being provided with a wall (perpendicular to the axis of said crank an having a port therein, means in said crank case rotatable therewith co-operating with said port to control the flow of as therethrough, said means being provi ed with an opening therein registerin with said port durin movement of sai iston away from sai crank case, and fan lades arranged in said opening to induce a flow of gas throu h said port into said crank case when sai openmg is in alignment with said port, said blades varying in pitch and the pitch of each blade bearing a definite relation to the position of said piston in said cylinder at the time such blade is in alignment with said ort.

7. an internal combustion engine, in combination, a crank case, a vertically disposed crank shaft rotatable therein, said crank case being rovided with a wall disposedperpendicu arly with respect to the axis of said crank shaft and havin a port therein, a throw of said crank sha t being formed to co-o crate with said wall to control the flow 0 gas through said port, and resilient means sup orti said crank shaft and urgling said t row mto contact with said we 8. In an internal combustion engine, in combination, a crank case having a lower wall, a vertically disposed crank shaft rotatable in said crank case, and means for supporting said crank shaft in said crank case comprising a thrust washer held against axial movement in one direction relative to said crank shaft and a coilspring surrounding said shaft and confined between said thrust washer and a surface of said lower wall, said lower wall being formed to provide an enclosure for said s ring and in which said thrust washer is sli ably receivable whereby to effect a dash got for dam ing vertical movements of sai crank sha t.

9. In an internal combustion engine, in combination, a crank case provided with an upper and lower wall, a vertically disposed crank shaft within said crank case, journals carried b said upper and lower walls for said cran shaft, and resilient means below the lower of said journals for supporting said crank shaft.

10. In an internal combustion engine of the two-stroke type, in combination, a crank case having an intake port in an end wall thereof, a crankshaft, a disc rotatable with said crankshaft and in contact with said wall, said disc havin an opening therein co-operating with saitf port to admit a flow of gas through said port into said crankcase during predetermined an lar positions of said crankshaft, and fan lades in said opening positioned to cut across said port when uncovered by said opening to accelerate the flow of gas into said crank case.

11. In an internal combustion engine of the two-stroke type, in combination, a crankcase having an intake port in an end wall thereof, a crankshaft, a disc rotatable with i said crankshaft and in contact with said wall, said disc having an opening therein cooperating with said port to admit a flow of gas through said port into said crank-case uring predetermined an lar positions of said crankshaft and fan lades carried by said disc and disposed within said opening in shearing relation with respect to said port for accelerating the flow of gas into said crankcase from said port.

12. In an internal combustion engine of the two-stroke type, in combination, a crank-case having an-intake port in an end wall thereof, a crankshaft, a disc rotatable with said crankshaft and in contact with said wall, said disc havin an opening therein co-operating with sai port to admit a flow of gas through said port into said crankcase durin predetermined angular positions of said crankshaft, a sleeve liner received in said opening, and fan blades carried by said liner co-operating with said port to accelerate the flow of gas through said pori;l when said opening is in alignment therewit 13. In an internal combustion engine of the two-stroke type, in combination, a crank-case having an intake port in an end wall thereof, a crankshaft, a disc rotatable with said crankshaft and in contact with said wall, said disc havin an opening therein co-tgierating with sail port to admit a flow 0 gas through said port into said crankcase during predetermined an lar positions of said crankshaft, a sleeve ner fitting into said opening and removably secured relative to said crankshaft and said disc, and fan blades carried by said sleeve liner for accelerating the flow of gas th rough said port when Said port is uncovered by said opening.

14. In an internal combustion engine of the two-stroke type, in combination, a crank c'ase having an intake port in an cud wall thereof, a crank-shaft rotatable in said crank-case, said crank-shaft having disc-like throws concentric to the main journals of said crank-shaft, a disc dis osed between said end wall and the ad aCent of said throws and normally closing said port, means for drivin said disc from said crankshaft, said disc aving an opening therein co-operable with said port to control the admission of gas into said crank-case in timed relation with the angular relation of said crankshaft, said adjacent throw having an opening therein in alignment with said opening in said disc, a liner sleeve fitting both of said openings and secured to said adjacent throw, and fan blades of the axial displacement type carried in said liner for accelerating the flow of gas through said port.

15. In an internal combustion engine, in combination, a crank-case having an intake opening therein, a crank-shaft rotatable in said crank-caseja throw of said crankshaft having an opening therein, and fan blades arranged in said opening in said throw to sweep across said opening in said crank-case in shearing relation to the flow thcrethrou h whereby to accelerate the flow throu h t e first mentioned opening into said cran r-case.

16. In an internal combustion engine, in combination, a crank-case, a cylinder projecting horizontall from said crank-case, a piston within sai c linder, a crankshaft rotatable in said cran -case disposed with its axis in generally vertical position, a connecting rod joining said crankshaft and piston, and resilient means co-operating besaid wall.

JAMES H. PIERCE.

tween said crank-ease and crankshaft to support the weight of said crankshaft and at leaist part of the weight of said connecting ro 17. In an internal combustion engine, in combination, a crank-case having an intake port in an end wall thereof, a crankshaft r0- tatable in said crank-ease, a throw of said crank-shaft being disc-like in form and bearing directly against said end wall around said port whereby to normally close said port, said disc-like throw having an opening therein adapted to uncover said port to the flow of gas into said crankshaft during predetermined rotational positions of said crankshaft.

18. In an internal combustion engine, in combination, a crank-case having an intake port in an end wall thereof, a crankshaft rotatable in said crank-case, a throw of said crank-shaft being disc-like in form and bearing directly against said end wall 

